Answer:
Reaction time tests can be used to assess an individual's hand-eye coordination. One test involves catching a 1 metre ruler and measuring the distance, d in metres, that the ruler travelled before being caught. The reaction time t seconds is then calculated using the formula: = √2d/9.8
Which statement did Kepler’s investigations of the movement of the planets explain?
Gravity acts on all objects in the universe.
Jupiter has more moons than earth.
Earth is not the center of the universe.
The sun is more massive than earth.
Question 7 (1 point)
Which of the following organelles helps organisms maintain homeostasis by controlling what substances may enter or leave cells?
Answer:
Cell membranes (plasma membranes) help organisms maintain homeostasis by controlling what substances may enter or leave cells.
An aqueous solution of nitrous acid hno2 has a ph of 1. 96. The ionization constant of this acid is 5. 0 × 10−4. How much nitrous acid was used to prepare one liter of this solution?.
The number of moles of nitrous acid used to prepare the solution is 0.0021 moles.
pH of the HNO2 solution = 1. 96
Concentration of the HNO2 solution = Antilog(-1.96) = 0.011 M
We have to set up the ICE table as follows;
HNO2(aq) ⇄ H^+(aq) + NO2^-(aq)
I 0.011 0 0
C -x +x +x
E 0.011 - x x x
The dissociation constant of the acid is 5.0 × 10−4
Hence;
5.0 × 10−4 = x^2/ 0.011 - x
5.0 × 10−4(0.011 - x ) = x^2
5.5 × 10^-6 - 5.0 × 10^-4x = x^2
x^2 + 5.0 × 10^-4x - 5.5 × 10^-6 = 0
x= 0.0021 M
The concentration of the acid (H^+) in the solution is 0.0021 M. The number of moles of the acid is obtained from;
0.0021 M × 1 L = 0.0021 moles
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If water turns deep red with a few drops of potassium thiocyanate, what cation is likely present?.
Answer:
Fe3^+
[tex]fe3 ^{ + } [/tex]
How to determine intermolecular forces.
Answer:
Incase you have H and F and another H and F
which best represents the number of moles in exactly 130 grams of potassium metal?
Answer:
if by EXACTLY means 130.0000, then the answer is 3.3250
by EXACTLY means 1.299 <Kmass<1.301 then the answer is 3.33
EXPLANATION
which best represents the number of moles in exactly 130 grams of potassium metal?
the elemental mass of K is 39.098
so exactly 130 divided by 39.098 = 3.3250
if by EXACTLY means 130.0000, then the solution is 3.3250 by EXACTLY means 1.299 <Kmass<1.301 is 3.33
What is Potassium Metal?
Potassium metal responds rapidly with atmospheric oxygen to create flaky white potassium peroxide in exclusively moments of exposure.
It stood preferably isolated from potash, the ashes of plants, from which its appellation derives.
In the systematic table, potassium is one of the alkali metals, all of which have a single valence electron in the outermost electron shell,
That is easily drawn to produce an ion with a positive charge a cation, that connects with anions to form salts. Potassium in disposition materializes only in ionic salts.
When the elementary mass of K is 39.098
Therefore, exactly 130 divided by 39.098 is = 3.3250
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Help please I promise this time I will mark whoever answers correctly first please
10 grams
mass does not change when cooking the egg
Which of the following shows a valid combustion reaction?
2Al + 2O2 → 2AlO + O2
C2H4 + 3O2 → 2CO2 + 2H2O
2CH4 + O2 → 2CO + 4H2
Ca + O2 → CaOH
Answer: C2H4 + 3O2 → 2CO2 + 2H2O
Explanation:
2Al + 2O2 → 2AlO + O2 Not Balanced Properly: 2Al + O2 = 2AlO
C2H4 + 3O2 → 2CO2 + 2H2O Looks Good
2CH4 + O2 → 2CO + 4H2 Not Correct: CO should be CO2
Ca + O2 → CaOH Not Balanced and No source for the H
Answer:
2H4+3O2 →2CO2+2H2
Explanation:
275 KJ of energy was transferred to water at 15c. Calculate the mass of water that can be brought to its boiling point
Answer:
need points rn sorry bro hope u get ur answer
Explanation:
What is carbon? What does it do?
Please help me no links
if good answer you get brainliest
Answer:
plutonic rocks are formed when magma cools and solidifies underground This shows us if the rock is plutonic or volcanic. When magma cools underground, it cools super slow and when lava cools above ground, it cools faster. When magma and lava cool, mineral crystals start to form in the molten rock.
Explanation:
i hope this is correct
how well did the landmases fit together this time
Answer:
The theory of continental drift is most associated with the scientist Alfred Wegener. In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other. He called this movement continental drift.
Explanation:
Calculate the molecular mass of the element
They give:H=1,AI=27,S=32,0=16,Cu=64,P=31,Mg=24,N=14,Na=23
Answer:
Na2SO4
2×23 + 32 + 4×16
46 + 32 +64
=142g
IS N2 (diatomic molecule of nitrogen considered a chemical compound can it be split into two or more simpler substances?
What is the acceleration of a 10 kg pushed by a 5N force
Answer:
0.5 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{5}{10} = \frac{1}{2} = 0.5 \\ [/tex]
We have the final answer as
0.5 m/s²Hope this helps you
What element does 'O' represent on the periodic table?
Answer:
OxygenExplanation:
which of the following best describes the relation ship between oxygen and chlorine
A. Oxygen and chlorine have the same symbols
B. Oxygen atoms have fewer protons than chlorine atoms
C. Oxygen and chlorine have the same properties
D. Oxygen atoms have twice as many protons as chlorine atoms
Answer:
B
Explanation:
The oxygen atoms have fewer protons than chlorine atoms:) hope this helps:))
According to the electronic configuration, oxygen atoms have fewer protons and electrons than chlorine atoms.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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Please help. A 208 g sample of sodium-24 decays. How much of this radioactive isotope will remain after 3 half
lifes?
Answer: The information about sequential order of the event occurred in the past can be obtained by using only relative dating method.
Explanation:
Relative dating method doesn’t give information about when it happened. It provides sequential order of the events. It is the art of deciding the overall happening of past occasions (i.e., the age of an item in contrast with another), without fundamentally deciding their outright age (for example evaluated age).
In topography, shake or shallow stores, fossils and lithologies can be utilized to correspond one stratigraphic segment with another.
HURRY for a BRAINLIST
Answer:
B
Explanation:
Answer:
answers
B
Explanation:
Explicaciónexplicacaca
What does the word "dutile" mean when used to refer to elements?
Answer:
capable of being hammered out thin, as certain metals; malleable.
Explanation:
what two elements are present in the compounds in the last two rows of table 4
Answer:could u expand on the question
Explanation:
Explain, in terms of particles, what happens when methane boils and why
the boiling point of methane is lower than that of butane.
Answer:Butane > ethane > methane, because between bigger molecules there are stronger van der Waals forces and also higher molar mass means they need to be given more energy to have enough kinetic energy to move quickly, freely in gas.
There are multiple butene isomers (Butene) and some (2-Butenes - cis and trans) actually have higher boiling point than n-Butane (there is also Isobutane, of course, with quite much lower boiling point than all of them) and some (1-Butene, Isobutylene) have lower, so this isn't really a fair or simple question. But on simplest level, it can again be said that 1-butene has lower boiling point because it has very similar shape but slightly lower molar mass (2H less) than n-butane.
Explanation:
Intermolecular forces such as dipole-dipole forces, London dispersion forces exist between molecules and these depend on strength of electronegativity of molecule. Therefore, methane converts to gas on boiling due to weak intermolecular forces of attraction between the molecules.
What is intermolecular forces of attraction?Intermolecular forces of attraction is force of attraction that make two molecule come closer. Intermolecular forces of attraction is directly proportional to the electronegativity of the molecule.
Size of electronegative molecule is small so, if any other molecule or molecule come into contact with this molecule then this molecule attract the electron of other molecule very efficiently and therefore the force between the molecule increases.
Molecules of methane have weak intermolecular forces of attraction. When energy is applied, the methane molecules easily break apart and turn into gas.
Therefore, methane converts to gas on boiling due to weak intermolecular forces of attraction between the molecules.
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if the column of water in the water barometer rose to a height of 36 feet, what would the atmospheric pressure be in mm hg?
The Atmospheric pressure is usually constant and is; 760mm Hg.
According bro the question;
The column of water in the water barometer rose to a height of 36 feet.The absolute pressure is given as;
P(abs) = P(atm) + P(gauge)The gauge pressure is dependent on the height of the water column.
Ultimately, the atmospheric pressure is constant and is given as; 760mm Hg.
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How does transfer of infrared energy relate to weather and climate conditions on Earth?
Answer:
Convection is the transfer of heat energy in a fluid. Air in the atmosphere acts as a fluid. The sun's radiation strikes the ground, thus warming the rocks. As the rock's temperature rises due to conduction, heat energy is released into the atmosphere, forming a bubble of air which is warmer than the surrounding air.
balance equation for H2O+O2-H2O2
PLZ HELP
What are 3 genetic disorders caused by either missing or extra chromosomes? Provide a brief short explanation of what causes the disorder and some potential symptoms.
Answer:
Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed.
Complex disorders, where there are mutations in two or more genius.
Hope it help^^
Brainliest me pls
400.0 mL of a 0.425 M solution of NaCl is diluted to 900.0 mL. What is the new concentration of the solution
The new concentration of the solution that has 400.0 mL of a 0.425 M solution of NaCl diluted to 900.0 mL is 0.189M
HOW TO CALCULATE CONCENTRATION:
The concentration of a diluted solution can be calculated using the following formula:C1V1 = C2V2
Where;
C1 = initial concentrationC2 = final concentrationV1 = initial volumeV2 = final volumeAccording to this question, a solution of NaCl has 400.0 mL of a 0.425 M solution and diluted to 900.0 mL. The new concentration is as follows:400 × 0.425 = 900 × C2
170 = 900C2
C2 = 170 ÷ 900
C2 = 0.189M
Therefore, the new concentration of the solution that has 400.0 mL of a 0.425 M solution of NaCl diluted to 900.0 mL is 0.189M.Learn more at: https://brainly.com/question/8795644?referrer=searchResults
assume you are performing the calibration step of experiment 8 and you begin with 80 g of water at 20 oc and 80 g of water at 80 oc. after adding the two portions of water into your calorimeter setup and following the procedure outlined in the experiment, you determine the temperature of the mixed portions of water to be 45 oc. what is the heat capacity of the calorimeter?
The heat capacity of the calorimeter is 133.76 J°/C.
A calorimeter is an apparatus employed when estimating the amount of heat required in a chemical reaction.
For the given calorimetric function:
the heat lost by the hot water = to the heat gained by the cold water and the calorimeter.These can be computed mathematically as:
[tex]\mathbf{m_wC_w\Delta \theta _w = m_cC_c\Delta \theta _c + C_{cal} \Delta_c}[/tex]
[tex]\mathbf{80 \ g\times 4.18 J/g^0 C \times (80-45)^0 \ C = 80 g \times 4.18\ J/g^0 \ \times (45- 20)^0 +C_{cal} \times (45- 20)^0 \ C}[/tex]
[tex]\mathbf{11704 \ J =8360 \ J+C_{cal} \times (25)^0 \ C}[/tex]
[tex]\mathbf{(11704 -8360) \ J= C_{cal} \times (25)^0 \ C}[/tex]
[tex]\mathbf{ C_{cal} = \dfrac{3344 \ J} { (25)^0 \ C}}[/tex]
[tex]\mathbf{ C_{cal} =133.76 \ J/^0 C}[/tex]
Therefore, the heat capacity of the calorimeter is 133.76 J°/C.
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Phosphorus reacts with oxygen to form diphosphorus pentoxide: 4 P(s) 5 O 2(g) ---> 2 P 2O 5(s) If 0.97 moles of phosphorus are reacted how many moles of P 2O 5 are produced
4P(s)+5O2(g)-->2P2O5(s)
4 moles of P=2moles of P2O5
0.97 moles of P=(2*0.97)/4
=0.485 moles
Convection currents are one force driving plate tectonics. What other force plays a major role?
Heat transfer
Gravity
Radioactive decay
Fossil formation
Answer:
Gravity
Explanation:
Gravity was founded by famous physician Sir Izak Newton.The gravity is a phenomenon by which every object in the universe attracts eachotherNewton discovered gravity by the falling apple from tree.The following factors contribute to plate tectonics: The Mantle's Convection. Mountain push gravitational force at the spreading ridges, Block pull gravitational force in subduction zones. Hence, option B is correct.
What is gravitational force ?The gravitational force, which is what pushes mass-containing objects toward one another. We frequently consider the pull of gravity from the Earth. Your body is kept on the ground by this force. However, all mass-bearing objects are pulled toward one another by gravity.
Population growth and changes in people's wants and activities are the main causes behind this. Changes in the overall levels of output and consumption are caused by these main movers.
The driving forces put strain on the environment through these modifications to production and consumption. In the direction of motion, gravity produces an active driving force.
Thus, option B is correct.
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